| Kinetics and mechanism of permanganate oxidation of iota- and lambda-carrageenan polysaccharides as sulfated carbohydrates in acid perchlorate solutions. | |
| | |
MedLine Citation:
|
PMID: 21872851 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
The kinetics of oxidation of iota- and lambda-carrageenan as sulfated carbohydrates by permanganate ion in aqueous perchlorate solutions at a constant ionic strength of 2.0moldm(-3) have been investigated spectrophotometrically. The pseudo-first-order plots were found to be of inverted S-shape throughout the entire courses of reactions. The initial rates were found to be relatively slow in the early stages, followed by an increase in the oxidation rates over longer time periods. The experimental observations showed first-order dependences in permanganate and fractional first-order kinetics with respect to both carrageenans concentration for both the induction and autoacceleration periods. The results obtained at various hydrogen ion concentrations showed that the oxidation processes in these redox systems are acid-catalyzed throughout the two stages of oxidation reactions. The added salts lead to the prediction that Mn(III) is the reactive species throughout the autoacceleration periods. Kinetic evidence for the formation of 1:1 intermediate complexes was revealed. The kinetic parameters have been evaluated and tentative reaction mechanisms in good agreement with the kinetic results are discussed. |
| | |
Authors:
|
Refat M Hassan; Ahmed Fawzy; Gamal A Ahmed; Ishaq A Zaafarany; Basim H Asghar; Hideo D Takagi; Yasuhisa Ikeda |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2011-7-26 |
Journal Detail:
|
Title: Carbohydrate research Volume: - ISSN: 1873-426X ISO Abbreviation: - Publication Date: 2011 Jul |
Date Detail:
|
Created Date: 2011-8-29 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0043535 Medline TA: Carbohydr Res Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Copyright Information:
|
Copyright © 2011 Elsevier Ltd. All rights reserved. |
Affiliation:
|
Chemistry Department, Faculty of Science, Assiut University, Assiut 71516, Egypt. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Oxygen therapy improves energy metabolism in focal cerebral ischemia.
Next Document: Simulating ventilation distribution in heterogenous lung injury using a binary tree data structure.